PoW-based Sybil Attack Resistant Model for Peer-to-peer Reputation Systems
LI Biao-qi1,FU Xiao-dong1,2,YUE Kun3,LIU Li1,2,LIU Li-jun1,2,FENG Yong1,2
1(Faculty of Information Engineering and Automation,Kunming University of Science and Technology,Kunming 650500,China)2(Yunnan Key Laboratory of Computer Technology Applications,Kunming 650500,China)3(School of Information Science and Engineering,Yunnan University,Kunming 650091,China)
Abstract：Reputation can help users make better decisions of services in the P2P system.However,Sybil attacker can obtain multiple identities and pretend to be multiple entities in the system.By manipulating the evaluation intentions of multiple Sybil nodes,the reputation of other participants can be changed according to the attacker's wishes.The existing prevention methods need to introduce a specific environment for attack detection or only have a single registration verification,which is difficult to suppress Sybil attack from the source.By introducing multiple rounds of PoW(Proof of Work)verification and dynamic difficulty adjustment verification mechanism,this paper proposes a Sybil attack prevention model for P2P reputation system.A sane attacker usually does not attack without gains,so we can minimize the attacker's expected gains by using multiple rounds of puzzle verification.In addition,considering that the attacker triggers a whitewashing attack to reapply for a node when performing a Sybil attack,the attacker's whitewashing attack is taken into consideration of the attack utility.The effectiveness of the model is verified through theoretical analysis and comparative experiments.
2022, Vol. 43 
